var _ = require("lodash");
// _.ceil(number, [precision=0])
// 向上取整，第二个参数是保留几位小数
console.log(_.ceil(4.006)); // 5
console.log(_.ceil(6.004, 2)); //6.01
console.log(_.ceil(6040, -2)); // 6100

// _.floor(number, [precision=0])
// 向下取整，第二个参数是保留几位小数
console.log(_.floor(4.006)); // 4
console.log(_.floor(0.046, 2)); // 0.04
console.log(_.floor(4060, -2)); // 4000

// _.round(number, [precision=0])
// 四舍五入，后面是精读
console.log(_.round(4.006));
console.log(_.round(4.006, 2));
console.log(_.round(4060, -2));
